Laminated plastic building material, such as that available under the trademark FORMICA, is usually sold in large sheets, four feet by eight feet being one common size. In view of the difficulty purchasers have in perusing through selections of such sheets, which may be available in hundreds of different colors and patterns, laminated plastic is commonly selected for purchase through the use of chain loops of small samples ("chips") of the available stock.
Sample chip loops are compact and lightweight. They are cheaply transportable by the manufacturer, easily restocked with new selections and can be taken home by the prospective purchaser for on-site comparison with the intended decor. Insofar as stock may be ordered for delivery from the manufacturer or from a central warehouse through the use of stock numbers printed on the chips, such sample loops can reduce the need for the retailer to keep a complete stock of expensive inventory.
Chip loops consist of scores of small pieces of laminated plastic, each typically about 2 inches by 3 inches, through which a conventional ball link chain (key chain) passes. The prior art method of assembling such loops has been to manually select one chip at a time from consecutive bins each containing chips of like color, pattern, composition or the like. Each succeeding chip is placed on top of the last, forming a collated stack of differing color, pattern, etc.
Each chip is pierced by a round hole of significantly greater diameter than the balls of the ball link chain. The loop is assembled by dropping the chain through the cylindrically aligned holes of the stack, lifting the stack and then securing the ends of the chain together.
U.S. Pat. No. 2,872,020 to O. Hansel et al. teaches a stacking apparatus for planar objects which could be converted for limited use to automatically form laminate plastic sample chip stacks. However, the Hansel apparatus is only capable of forming stacks of a height which is limited by the height of vertical tines--the stack can be no higher than the tines, whose height is in turn limited by the torque which a revolving conveyor chain can support. Thus, there is a need in the art for an automatic stacking apparatus which can collate and stack scores, if not hundreds, of laminate chips for forming into sample loops.